Denzler



Feb.. '7, 1956 B. Dr-:NZLER 2,733,925

COLLET CHUCK Filed Feb. 14, 1952 2 Sheets-Sheet 1 IN VEN TOR.

B rthold Den ler Feb. 7, 1956 B, DENZLER 2,733,925

COLLET CHUCK Filed Feb. 14, 1952 2 Sheets-Sheet 2 INVENTOR.

B rthold Demler H "CQILE'TCHUCK Berthold Denzler, nChicago, dll., assigner ato :Davos .Products Company,Chicago, ..Ill.,'.a.copartnership consisting of Berthold Denzler and Filip Erandhandler Application February 14,1952, Serial No. @71,581

'12 fClaims. t (Cl. .27-9-43) The present invention relates to :collet chucks and vmore particularly tocollet chucks .of the .type `shown and -described inmyfprior :Patent No..2,561,788rdatedluly 24, 1951, -for Collet Chuck, over Awhich the ,present vchuck is designedas an improvement. Y

The objects of thev'present invention are, in general, substantially the same as :those Aoutlined .in .the abovementioned rpatent relating .to leconomy of manufacture and reliability in operation, but `it is la particularobject of the present inventiontoqprovide fa-collet chuck of ,this type having associated .therewith a :removable adapter sleeve designed -for receptiontherein `of the .collet proper and whichis capable ofhaving substituted therefor asimilar adapter sleeve f of different diameter .to ,accommodate reception cfa collet of differentsizetand,capable of handling a different workpiece, all without ,disturbing the normal :manner of functioning of Vthe vchuck assembly asa whole.

A similar object Aof the zinvention'is to provide a .collet chuck of this .character inwhiehthe adapter sleeve, vin addition .to :periormingits function as an ;adaptor, also constitutes the .actual `constricting sleeve :employed .for the gpurpose .of compressing .or .Lconstricting .the .collet jaws :and f causing them .to :perform ltheir clamping action on the workpiece.

A -furtherfobject :of the invention 'is toprovide 4sa..collet chuck of this .type having vassociated :therewitha collet draw ling whichis shiftable .axially fof the chuck and which fthreadedly receives therein :an end of ,the .collet proper, together with'nove'l means ,forlocking'ttheicollet relative to the draw ring 1in any :desired .position of threadedadjustmentin ordento vary theteffectivestroke ofthe draw plate. 'lncarrying out'thislast mentioned object, the invention contemplates 4the :provision vof .a iloating locking ring which isconstrained fto follow-fthe rotational-movements yof thecollet proper fwhen:thelatter is threaded into or Aoutl of -the draw ring 'l and fWh-ich may itself be securely locked in any desiredlangulanposition of Iadjustment to thereby lock -the collet *against further turning movement relative to 'the draw 'ring and fattain a desired setting of the colletfaxially'relativeftothe draw ring. 'By such an arrangement the more obviousexpedient of utilizing set screws which might otherwisefdamage the colletithreads is obviated.

A similar and related-object of the invention-in a-moditied form thereof is'to'provide a colletfchuck of-thegtype outlined above in which the floating'loc'king ring for locking the .chuck proper `in any desired angular positionfo'f adjustment is disposed at'the forward end of the *chuck assembly in a position whereiit is conveniently accessible for manipulation to exert adelatively large torque 'leverage on the collet `properfor adiustingpurposes prior 'to locking of the ring to establish `a `fixed position rof `the chuck.

A still further object of the'invention is to provide a collet chuck ofthe type briefly outlined 4above including a collet draw ring'from'whichthe collet proper 'isireadily removable and having associated l"therewith `:means 'for retaining the draw ring in its assembled position'within the chuck assembly after the `collet "has 'been 4removed nited States Patent O F 2,733,925 `ifbatented Feb. 7, ...1.956

'2 from the chuck and the latter has been .removed from the lathe or other machine tool with which the chuck may be associated.

YA related lobjectof-.the.invention.is to provide acollet chuck .assembly in which .the retaining means for the collet draw ring also constitutes `a part of a spring'biasing means 4whereby the draw ring is normally vurged to its inoperative positionagainst,the-action of the clutch mechanism ordinarilyemployed for moving the draw ring to its .operativecollet rconstrictingfposition.

Yet .another objectof the-invention, ina collet chuck of the Icharacter-shown.and .described in my above-mentioned patent, is to provide a removable stop ring which, when in positionfin the yclutch-assembly,flimits the movement .of the clutch sleeve employed in connection with the chuck assembly in one direction, as well as preventing removal ofthe-sleeve fromitssliding support on the chuck housing.

The provision :of Aan improved collet .chuck which is relatively ,simple -in tits construction; one Awhich is comprised `of .a yminimum .number of .relatively moving parts and which is therefore `.unlikely to x get out of vorder; one which is rugged .and Adurable and which is ,therefore possessed of long life; 'and :one which ,is positive in its actionandwhich v:is otherwise welladapted to perform the servicesrequiredzof it, are furtherdesirable features that'zhave beenbornerinmindin'the production and developmentsof the present invention.

ln -theJa-ceompanying vdrawings forming a part of this speciiication, one embodimentfof .they invention 'has been disclosed.

iin the :drawings:

Fig. l is a side elevational view of a collet chuck assembly. manufacturedrin accordance with thelprinciples ofi-the present invent-ion.1n`this -view `certain parts yhave been Sbroken away Yto'morec1early=revealLthe ynature of the invention;

Fig. 2fis `a frontfelevati'onal viewvof the chuck assembly shown? in 1F ig. rLl;

lFig. 3 is a sectional view taken substantially alonglthe line of Fig. I'2 iin the direction `indicated by 1the arrows;

LlFig. 4fis a sectional =view takensubstantially alongathe line 4-24 'df'Fig 3 5in 'the ldirection indicated by the arrows;

IFig. `5 is -a sectional View "takenlsubstantially along the line 5 5 of Fig t3 vin the "direction rindicated 'by A'the arrows;

iFig. 6 isa sectionalrvievv, `similar to Fig. 3, taken substantially centrally vthrougha modified fforrn of the chuck assembly;

`Fig.'7 "is na :front end'view lof the `assembly shown in Fig. 6; and

sFig. V8 is a rear -endview of the 'chuckassembly sho-wn in Fig. Y6 with 'the cover and retaining plate for the draw ring removed'to more'clearly illustrate certain features 'of the invention.

In all `of the 'above "described views similar characters of reference are employed to designate similar parts throughout.

Referring-now tothe drawings-in detail, lthe improved collet y'chuck assembly comprising the present invention involves 'in its ,general Aorganizationa chuck housing :10 includinga cylindrical y-body'portion l2 from which'there projects radially outwardly -a peripheral `attachment or mounting llange i4 at therearfend thereofand lprovided with asei'ies 'of spaced holes '16 designed for reception therethrough oftheusual'attachment bolts "18 by'means ofwhichthe'chuck assembly may -be attached to a suitable "support 20 whihmaybetthe rotatable head of a machinetoolor `Vwhichmay Jbe' a stationary support. The

3 cylindrical body portion 12 of the chuck housing 10 is adapted to receive therein the collet proper 22, a surrounding adapter sleeve 24, a floating locking ring 26, a draw ring 28, and a draw ring retaining assembly 30, the nature and function of which will soon be made apparent.

The chuck housing is formed with a cylindrical bore 32 therein and an enlarged counterbore 34 at the rear end thereof providing a shoulder 36 (Figs. 3 and 5). The draw ring 28 is in the form of a ring-like member having a central threaded opening 38 therein surrounded by a rearwardly extending annular flange 40. The draw ring 28 is slidably disposed within the counterbore 34, in which it has a silding fit, and the forward face thereof is adapted to bear against the shoulder 36 when the draw ring is in its normal retracted position as shown in Fig. 3.

The draw ring 28 is held against rotation relative to the housing 10 by means of a pin 39 which projects forwardly from the shoulder 36 and which extends into a longitudinally extending groove 41 provided in the outer face of the draw ring.

The draw ring 28 is normally maintained in its retracted position by means of a spring 42 one end. of which bears against the draw ring and the other end of which bears against a split snap ring 44 mounted within a narrow internal groove 46 provided adjacent the extreme rear end of the counterbore 34. The annular flange 40 provides a centering rib for the forward end of the spring 42 and the split ring 44 provides a seat for the other end of the spring. The groove 46 serves to prevent the ring 44 from axial tilting movement within the counterbore 34. A pair of inwardly extending fingers 48 formed at the split ends of the ring 44 provides a means whereby the ring may be engaged by a suitable contracting tool for removal of the ring from the counterbore 34.

The collet proper 22 is in the form of a cylindrical member preferably formed of hardened steel and having a body portion 50 having an enlarged head 52 at its forward end providing an annular exterior conical surface 54 which may be separated from the outer cylindrical surface of the body portion 50 by means of a shallow annular groove 56. The rear end of the collet 22 is exteriorly threaded as at 58 and the threaded portion thereof is designed for different degrees of threaded reception within the threaded opening 38 provided in the draw ring 28 for collect adjusting purposes in a manner and for a purpose that will be described presently.

The collect 2 is axially slidable within the central bore 60 of the adapter sleeve 24, the latter being in the form of a tubular member which is press tted within the cylindrical bore 32 of the housing 10 and the rear end 62 of which terminates a slight distance forwardly of the shoulder 36 which divides the bore 32 from the counterbore 34. A shallow internal flange 64 is formed at the rear end of the adapter and bears against the body portion 50 of the collet 22 and the forward end of the adapter sleeve 24 is provided with a conical surface 66 designed for camming engagement with the exterior conical surface 54 provided on the collect 22 for collet constricting purposes in a manner that will be described presently.

The tubular collet 22 is provided with a plurality of longitudinally extending slits 68 (Figs. 2 and 3) therein which extend completely through the head 52 and rearwardly of the body portion 50 throughout a major portion of the lengthof the collet tube. While any number of such slits may be provided, for illustrative purposes three have been shown spaced 120 apart thus dividing the head into three jaws 70 in the usual manner of forming such collets. It will be seen, therefore, that with the collet 22 threadedly received in the opening 38 of the draw ring 28 to the desired degree, and with the draw ring bearing against the internal shoulder 36 provided in A the housing 10 under the influence of the spring assembly 30, a slight space will exist between the conical surfaces 54 and 66 provided on the collet head 52 and adapter sleeve 24, respectively. Upon sliding movement of the draw ring 28 rearwardly in the counterbore 34, the entire collet proper 22 will be moved rearwardly in the adapter sleeve 24 so that the conical surface 54 of the collet 22 will be drawn against the conical surface 66 of the adapter sleeve to force the collet jaws 70 inwardly and thus contract or constrict the collet against the workpiece held therein.

Means are provided for moving the draw ring 28 axially to cause the collet jaws to grip or release the workpiece and, toward this end, a pair of diametrically opposed slots 72 are formed in the chuck housing and exist partially in the mounting flange 14 and partially in the cylindrical bore portion 12 thereof. Each slot 72 has pivotally mounted therein a clutch dog 74 carried on a pivot pin 76 extending across the slot 72. The pivot pins 76 are disposed within chordal bores 78 which are drilled in the mounting flange 14 to permit insertion of the pins 76 in position across the slots 72.

Each dog 74 is formed with a cam surface S0 designed for camming engagement with the forward face of the draw ring 28. A clutch linger 82 formed on each dog normally projects from the confines of the slot 72, as shown in Fig. 3. The lingers 82 are capable of being moved into the slot 72 in such a manner as to cause the clutch dogs 74 to be swung about the axes of its pivot pins 76 so as to cause the shoulder 80 thereof to bear against the forward face of the draw ring 28 and to move the latter rearwardly against the action of the spring 42 to draw the collet 22 rearwardly in the chuck assembly and constrict the same in the manner previously described.

Cooperating with the fingers 82 of the clutch dogs 74 is an axially shiftable clutch sleeve 84 in the form of a cylindrical member having a central bore 86 extending therethrough which is slidably received on the outer cylindrical surface of the body portion 12 of the housing 10. The sleeve 84 is formed with an offset portion 88 extending rearwardly therefrom and provided with an internal conical cam surface 90 in register with the ends of the dog lingers 82 and with an inner cylindrical surface 91. The sleeve 84 is also formed with an external annular groove 92 into which there is adapted to extend a pair of diametrically opposed lingers 94 that project inwardly from the medial ring portion 96 of an operating lever 98, the lower end of which is pivoted as at 100 to a suitable standard 102 bolted as at 104 to the machine tool or other stationary support adjacent the collect chuck. A pair of floating shoes 106 are positioned in the annular groove 92 and substantially bridge the distance between the two fingers 94.

From the above description it will be seen that swinging movement of the operating lever 98 in a counterclockwise direction as viewed in Fig. l about the pivotal axis 100 Will cause movement of the clutch sleeve 84 to the left, thus bringing the conical bearing surface 90 thereof into engagement with the projecting fingers 82 of the clutch dog 74 and, by a camming action, retract the fingers into the slots 72 provided for them in the housing 10. Such movement of the dogs 74 will cause the shoulders 80 to bear against the forward face of the draw ring 28 and move the latter to the left as viewed in Fig. 3 against the action of the spring 42 to thus draw the collet proper 22 to the left so that the conical surfaces 54 and 66 will engage each other in a manner previously described to constrict the collet against the workpiece. As the clutch sleeve 84 moves toward its extreme left hand position as viewed in Fig. 3, the ends of the fingers 82 ride off of the conical surface 90 and onto the cylindrical surface 91, thus maintaining the fingers 82 retracted and eleminating any tendency for the spring 42 to operate through the dogs to restore the clutch sleeve 84 to its position of release.

Movement of the lever -98 Zin a c-iloelwvise V"direction will reverse `the -functioning ofthe clutch dogs 74 to -relieve the pressure rthereof against the forward face of the draw ring 28 to permit the spring 42 ytoreturn the draw ring toits position of engagement with'theshoulder 36, thus moving the collet 22 -to the right as vviewed in Fig. 3 and relieving the pressure 'between -the conical surfaces 54 and-66 to Aexpand the collet jaws 70 by the action f of their inherent resiliency.

lnorder to limit-the forward-movement of the clutch sleeve-S4 on the housing 10,'a stop ringl1071is threadedly received on the extreme forward end of the adapter sleeve 24 and has an overall diameter greater than the internal diameter of the clutch sleeve 84 so that the latter may bear against the yring 107 whenin its forward orreleased position.

As previously stated, therear end of the'collet is threadedly received in the draw ring'28 and the extent of its threaded yreception in the iring determines the elfective stroke ofthe draw ring. Thus by rotating the collet 22 relative to the draw=ring`28 in-such a direction as to shift the collet bodily to the right yas `viewed in Fig. r3, the eiective stroke-of the draw yringZS isflessened sothat the extent of camming action between the conical surfaces 54 and 66 is reduced with a consequent diminution in the constriction of the collet when the lever V98 is moved to its operative poistion.

In order that the collet 22 may be securely held in any-desired axial `position-ofadjustmentlrelative to the draw ring 28v the oating locking ring 26, previously mentioned, is providedand is disposed within the bore 32 of the housing -10 immediately forwardly of the shoulder 36 and directly behind the'rear-end 62 of the adapter sleeve '24. The ring 26 carries an inwardly projecting key in the form of a radially disposed `pin 10S which extends into a longitudinally extending groove 110 provided in the rear end ofthe collet A22. The ,ring 26 is thus constrained yto follow the Arotational movements of the collet 22 when thelatter-is Yturnedrelativeto the draw Vring 28 for adjustment purposes. An elongated set screw-112 extends Iradially-throughthe-mounting ange '14 of the housing 10 and the-Sinner endthereof is adapted to bear against the bottom Vsurface of a shallow annular groove or trough 114 provided in the flocking lring 26 when the set screw 112 is tightened'thereagainst. Tighteningof the set screw 112 thus Vlocks the ring 26 in a fixed position relative to the housing and thereby in turn locks the collet against turning movement-relative 'to the draw ring 28 which itself is held againstturning movement relative to the housing by meansof Vthe pin and slot connection 39 and 41 previously described. It will be "seen that upon backing up of the set `screw 1,12 'thelocking ring 26 will be released for rotational movement with the collet 22 and the latter may be turned relativeto the draw ring 28 to any desired position of axialadjustment, after which the set screw 112 may again be-tghtenedtolock the collet in its adjusted position. The provision of the locking ring 26 which turns bodily with'the collet 22 provides a means for effectively locking the kvcollet in position .without damaging the ythreaded portion of the .collet ywhich would ordinarily be the vcaseif a conventional set ,screw were employed and designed =for ,engagement with the threaded portion of the collet.

A cylindrical cover nsleeve `116is telescopically received over the mounting iiange 14 ,and-is providedwith a conical forward kouter surface 118 and ia reduced bore portion 120 providing a shoulder 122 which .-bears against the forward face of the mounting ange. The rear end of the oifset portion 88 of the clutch sleeve 84-.is adapted to extendinto the bore 120 and is movable axiallytherein with a close fit whenthe clutch-'sleeveg84 is `shifted in either direction. A hole or opening A124 is provided in the :cover sleeve116-andis designed forzregistry with the outer end of the set screw'1121tofacilitate manipulation of -thelatter by insertion of -a suitable tool 'through the opening 12'4.

VFrom thefabove description'it is thought ythat'the construction, operation and many advantages-of the herein described collet chuck will `be thoroughlyfunderstood. It may be :pointed out, however, that when it is desired-to substitute a collet 22 of different size for accommodating diiferent types of work, the adapter sleeve 24 may be driven or pulled from'its pressed t within the cylindrical bore 32 of the housing 10 and a different adapter sleeve having a largeror smaller internal diameter, as the case maybe, may be substituted in its-stead'by Vforcing the same into `thebore l-32 with-a pressed vfit.

Itwill vvbe understood that when a particular adapter has 'been installed within Athe :bore 32 of the housing 10, the composite housing and adapter sleeve 24 in effect constitute a unitary chuck casing. The centralbore of the adapter sleeve 24 4thenbecomes the central bore ofthe composite casing in which a collet 22 of selected size is slidable.

fReferring now-to Figures 6, `7 and 8 wherein'a modiied form of chuck assembly constructed in accordance with the principles of-thewpresent invention has been illustrated, this form of the invention is similar yin some respects tothe previously described form ofthe invention shownin Figures 1 to 5 inclusive, the main distinction being that the locking :ring v26 together with its radially disposed locking pin 4108 has been omitted and its function accomplished by the provision of a manually accessible lockingring 26 havinglassociated therewith ya 'locking lug 108 projectinginto an axial groove 116' machined inthe forward region of the collet proper 22. The nature and :function of lthis modified form of locking means and its relation to the lcollet chuck lassemblywill now vbe more fully described.

inasmuch -as the collet chuck assembly of Figures 6 to 8 inclusive possesses many features and instrumentalitiesin vcommon with the chuck assembly in lFigures l to 5 inclusive, a detailed description of this latter chuck assembly is nnot deemed 'necessary and an understanding thereofmay be had byreference to 'Figures 6 to v-8 linclusive-in the drawings, wherein similar characters of referenceihave been-applied to the corresponding parts of the two chuck assemblies.

Referring now to .'Figure, the vchuck housing I10 remains lsubstantiallythe same as in the form of the'invention shown in Figure 3. inasmuch as no provision for an adapter such as the adapter l24-is made in the moditied form illustrated, the housing 10 and collet proper 22 -are provided with cooperating mating vsurfaces 66 and V54 respectively, designed vfor camming engagement with eachother when the draw ring'28 is shifted axially by the fingers 82 of the clutch dogs 74 under the control yof the clutch sleeve 84'.

The draw ring 28 is normally urged in a forward direction by means of a coil spring 42 one end of which bears against the draw ring 28 and is centered thereon bymeans of the flange 40 and the other end of which bears against a removable retaining ring or end piece 44. Countersunk attachment screws 45' are employed for securing the retaining ring 44 to the flanged portion 14 ofthe housing.

lfheiioating locking ring 26' which has been substituted for lthe locking ring 216 includes a peripheral rim portion 27 which surrounds the forward end of the chuck'housing itl. A pair of diametrically opposed set screws iii extends through the rim portion 27' and into an annular groove 29 in the forward regions of the'housing 1G. An inwardly extending flange 31 is provided in the forward regions ofthe rim 27 and is adapted to overlie the annular front face of the housing lil'. The groove 110 extends axially through the thickened front region of the collet proper 22 and the lugjlilt projects inwardly from the flange 31' and intoy the groove.

From the `above description it will be seen that tightening of the set screws 112' will serve to lock the ring 26' in a fixed position relative to the housing to thereby in turn lock the collet proper 22 against turning movement relative to the draw ring 28', which itself is held against turning movement relative to the housing by means of the pin and slot connection 39', 41 (Fig. 8), similar to the pin and slot connection 39, 41 of Fig. 5. Upon backing up of the set screws 112 the locking ring 26 will be released for rotational movement with the collet 22' and the latter may thus be turned through the medium of the ring 26' to any desired position of axial adjustment, after which the set screws 112 may again be tightened to lock the collet 22' in its adjusted position.

Because of the relatively large external diameter of the locking ring 26 relative to that of the collet proper 22' an increased degree of torque leverage may be applied to the collet through the medium of the ring 26 to etect such adjustment of the collet. The ring 26 when in position on the housing 10 limits the forward movement of the clutch sleeve 84.

In compliance with the requirements of the patent statutes I have here shown and described a preferred ernbodiment of my invention. It is, however, to be understood that the invention is not limited to the precise construction here shown, the same being merely illustrative of the principles of the invention. What I consider new and desire to secure by Letters Patent is:

l. In a collet chuck assembly, a housing providing a cylindrical bore, an adapter sleeve removably but tixedly secured within said bore, a collet slidably disposed within and projecting through said sleeve, said collet having a plurality of normally expanded, yieldable and contractible jaws, cooperating cam means on said adapter sleeve and collet for contracting said jaws upon movement of the collet axially and rearwardly within said sleeve, a draw ring slidably disposed within said bore rearwardly of the sleeve, means for preventing turning movement of Said draw ring in said bore, the rear end of said collet being threaded into said draw ring whereby rotational turning movement of the collet relative to said adapter sleeve will etect axial movement of the collet relative to the draw ring, cam means carried by said housing for engaging said draw ring and moving the latter rearwardly in said sleeve to contract the jaws of said collet, and means for locking said collet against rotational turning movement relative to the draw ring in any desired position of adjustment with respect thereto.

2. In a collet chuck assembly, a housing providing a cylindrical bore, an adapter sleeve removably but lixedly secured within said bore, a collet slidably disposed within and projecting through said sleeve, said collet having a plurality of normally expanded, yieldable and contractible jaws, cooperating cam means on said adapter sleeve and collet for contracting said jaws upon movement of the collet axially and rearwardly within said sleeve, a draw ring slidably disposed within said bore rearwardly of the sleeve, means for preventing turning movement of said draw ring in said bore, the rear end of said collet being threaded into said draw ring whereby rotational turning movement of the collet relative to said adapter sleeve will effect axial movement of the collet relative to the draw ring` cam means carried by said housing for engaging said draw ring and moving the latter rearwardly in said sleeve to contract the jaws of said collet, a locking ring disposed within said bore and surrounding said collet, means constraining said locking ring to follow the rotational movements of the collet while permiting relative axial movement therebetween, and means for releasably holding said locking ring against rotation in said bore.

3. ln a collet chuck assembly, a housing providing a cylindrical bore, an adapter sleeve removably but iixedly secured within said bore, a collet slidably disposed within and projecting through said sleeve, said collet having a plurality of normally expanded, yieldable and contractible jaws, cooperating cam means on said adapter sleeve and collet for contracting said jaws upon movement of the collet axially and rearwardly within said sleeve, a draw ring slidably disposed within said bore rearwardly of the sleeve, means for preventing turning movement of said draw ring in said bore, the rear end of said collet being threaded into said draw ring whereby rotational turning movement of the collet relative to said adapter sleeve will etfect axial movement of the collet relative to the draw ring, cam means carried by said housing for engaging said draw ring and moving the latter rearwardly in said sleeve to contract the jaws of said collet, a locking ring dise posed within said bore and surrounding said collet, means constraining said locking ring to follow the rotational movements of the collet while permitting relative axial movement therebetween, and a set screw extending through said housing and having its inner end in register with said locking ring and designed for engagement with the latter for holding the same against rotational turning movement in said bore to thereby lock said collet against turning movement relative to said draw ring.

4. In a collet chuck assembly, a casing providing a cylindrical bore and an enlarged counterbore in communication therewith rearwardly thereof and accessible through an opening in the rear of the casing, a collet slidably disposed within and projecting through said bore, said collet having a plurality of normally expanded yieldable contractible jaws, cooperating cam means on said casing and collet for contracting said jaws upon movement of the collet axially and rearwardly within said bore, a draw ring slidably disposed within said counterbore, means detachably securing the rear end of said collet to said draw ring for movement of the collet and ring in unison, cam means carried by said easing for engaging said draw ring and moving the latter rearwardly in said counterbore to contract said jaws, means providing an internal groove in the defining walls of said counterbore, a snap ring disposed within said groove which prevents axial tilting thereof, and a coil spring disposed within said counterbore and bearing at one end against said snap ring and embracing a centering neck on said draw ring at the other end and bearing against a shoulder on said draw ring and serving to normally urge the draw ring forwardly in the counterbore.

5. In a collet chuck assembly, a housing providing a cylindrical bore, a collet slidably disposed within and projecting through said bore, said collet having a plurality of normally expanded, yieldable and contractible jaws, cooperating cam means on said housing and collet for contracting said jaws upon movement of the collet axially and rearwardly within said bore, a draw ring slidably disposed within said bore rearwardly of the housing, means for preventing turning movement of said draw ring in said bore, the rear end of said collet being threaded into said draw ring whereby rotational turning movement of the collet relative to said adapter sleeve will effect axial movement of the collet relative to the draw ring, cam means carried by said housing for engaging said draw ring and moving the latter rearwardly in said sleeve to contract the jaws of said collet, a locking ring having a rim portion surrounding said housing, means constraining said locking ring to follow the rotational movements of the collet while permitting relative axial movement therebetween and means for releasably holding said locking ring against rotation on said housing.

6. In a collet chuck assembly, a housing providing a cylindrical bore, a collet slidably disposed within and projecting through said bore, said collet having a plurality of normally expanded, yieldable and contractible jaws, cooperating cam means on said housing and collet for con tracting said jaws upon movement of the collet axially and rearwardly within said bore, a draw ring slidably disposed within said bore rearwardly of the housing, means for preventing turning movement of said draw ring in said bore, the rear end of said collet being threaded into said draw ring whereby rotational turning movement of the collet f o, an

afrsspae relative to said housing will eiect axial movement of the collet relative to the draw ring, cam means carried by said housing for engaging said draw ring and moving the latter rearwardly in said bore to contract the jaws of said collet, a locking ring having a rim portion surrounding said housing and an inwardly extending flange forwardly of said housing, there being an axially extending groove formed in one of said collet jaws, a lug projecting inwardly from said flange and extending into said groove, there being an annular groove formed in said housing exteriorly thereof and a set screw extending through the rim portion of said locking rim and into said annular groove for locking the ring, and consequently the collet, in any desired position against turning movement relative to the housing.

7. In a collet chuck assembly, a casing providing a cylindrical bore and an enlarged counterbore in communication therewith rearwardly thereof, a collet slidably disposed within and projecting through said bore, said collet having a plurality of normally expanded yieldable contractible jaws, cooperating cam means on said casing and collet for contracting said jaws upon movement of the collet axially and rearwardly within said bore, a draw ring slidably disposed within said counterbore, said draw ring being internally threaded, the rear end of said collet being externally threaded and threadedly received Within said draw ring for axial adjustment relative thereto upon relative turning movement between the collet and draw ring, means preventing rotational turning movement of said draw ring within said counterbore, and means for locking said collet in any selected position of adjustment relative to the draw ring, said locking means comprising a locking ring having a rim portion surrounding said housing, means constraining said locking ring to follow the rotational movements of the collet While permitting relative axial movement therebetween, and means for releasably holding said locking ring against rotation on said housing.

8. In a collet chuck assembly, a casing providing a cylindrical bore and an enlarged counterbore in communication therewith rearwardly thereof, a collet slidably disposed within and projecting through said bore, said collet having a plurality of normally expanded yieldable contractible jaws, cooperating cam means on said casing and collet for contracting said jaws upon movement of the collet axially and rearwardly within said bore, a draw ring slidably disposed within said counterbore, said draw ring being internally threaded, the rear end of said collet being externally threaded and threadedly received within said draw ring for axial adjustment relative thereto upon relative turning movement between the collet and draw ring, means preventing rotational turning movement of said draw ring within said counterbore, and means for locking said collet in any selected position of adjustment relative to the draw ring, said locking means comprising a locking ring having a rim portion surrounding said housing `and an inwardly extending ange forwardly of said housing, there being an external axially extending groove formed in said collet, a lug projecting inwardly from said ilange and extending into said groove, and a set screw extending through the rim portion of said locking rim for locking the ring, and consequently the collet, in any desired position against turning movement relative to the housing.

9. In a collet chuck assembly, a housing providing a bore, a collet slidably disposed within said bore, said collet having a plurality of normally expanded, yieldable and contractible jaws, cooperating cam means associated with said housing and collet for contacting said jaws upon movement of the collet axially and rearwardly within said housing, a draw ring slidably disposed within said bore, means for preventing turning movement of said draw ring in said bore, one end of said collet being threaded into said draw ring whereby rotational turning movement of the collet relative to said housing will eiect axial movement of the collet relative to the draw ring, means carried by said housing for engaging said draw 10 ring and moving the latter rearwardly in said housing to contract the jaws of said collet, and means for locking said collet against rotational turning movement relative to the draw ring in any desired position of adjustment with respect thereto.

10. In a collet chuck assembly, a housing providing a bore, a collet slidably disposed within said bore, said collet having a plurality of normally expanded, yieldable and contractible jaws, cooperating cam means associated with said housing and collet for contracting said jaws upon movement of the collet axially and rearwardly within said housing, a draw ring slidably disposed within said bore, means for preventing turning movement of said draw ring in said bore, one end of said collet being threaded into said draw ring whereby rotational turning movement of the collet relative to said housing will eiect axial movement of the collet relative to the draw ring, means carried by said housing for engaging said draw ring and moving the latter rearwardly in said housing to contract the jaws of said collet, a locking ring adjacent to said collet, means constraining said locking ring to follow the rotational movements of the collet while permitting relative axial movement therebetween, and means for releasably holding said locking ring against rotation.

1l. In a collet chuck assembly, a housing providing a bore, a collet slidably disposed within said bore, said collet having a plurality of normally expanded, yieldable and contractible jaws, cooperating cam means associated with said housing and collet for contracting said jaws upon movement of the collet axially and rearwardly within said housing, a draw ring slidably disposed within said bore, means for preventing turning movement of said draw ring in said bore, one end of said collet being threaded into said draw ring whereby rotational turning movement of the collet relative to said housing will eiect axial movement of the collet relative to the draw ring, means carried by said housing for engaging said draw ring and moving the latter rearwardly in said housing to contract the jaws of said collet, a locking ring adjacent to said collet, means constraining said locking ring to follow the rotational movements of the collet while permitting relative axial movement therebetween, and a set screw extending into said housing and having one end in engagement with said locking ring for holding the same against rotational turning movement to thereby lock said collet against turning movement relative to said draw ring.

12. In a collet chuck assembly, a housing providing a bore, a collet slidably disposed within said bore, said co1- let having a plurality of normally expanded, yieldable and contractible jaws, cooperating cam means associated with said housing and collet for contracting said jaws upon movement of the collet axially and rearwardly within said housing, a draw ring slidably disposed within said bore, means for preventing turning movement of said draw ring in said bore, one end of said collet being threaded into said draw ring whereby rotational turning movement of the collet relative to said housing will eiect axial movement ot the collet relative to the draw ring, means carried by ysaid housing for engaging said draw ring and moving the latter rearwardly in said housing to contract the jaws of said collet, a locking ring adjacent to said collet, one of said collet and locking ring having a projection which iits into an axial slot in the other of said members thereby constraining the locking ring to follow the rotational movement of the collet while permitting relative axial movement therebetween, and means for releasably holding the locking ring against rotation.

References Cited in the le of this patent UNITED STATES PATENTS 1,535,048 Schumer Apr. 21, 1925 1,864,786 Wilkins June 28, 1932 2,311,258 Sjogren Feb. 16, 1943 2,561,788 Denzler July 24, 1951 2,585,747 Denzler Feb. 12, 1952 

